In the production and merchandising of goods, it is often desirable to make use of removable coupons or labels contained on containers or packages that function as redeemable retail coupons, inventory control labels, and the like. In these functions, it is desirable and often necessary that the coupon label not be prone to premature detachment during shipping and handling, yet be readily and cleanly removable.
Furthermore, inventory control labels, especially those affixed to reusable containers, are subject to abrasion during shipping and handling and to chemical attack by spillage of the container contents. Abrasion and chemical attack can destroy important information and result in premature detachment of the label and, in the case of relabeling, can increase the difficulty in removability of the label.
U.S. Pat. No. 4,767,654, to Riggsbee “DETACHABLE COUPON LABEL”, describes a label structure appropriate for attaching to packages or containers which permits the coupon label to be readily detached without leaving a tacky residue and without the use of a coated release substance. Specifically, Riggsbee requires the use of London or dispersion forces to attach the coupon at a desirable release force, in the range of 10-100 g/inch width, to a base sheet without making use of either an adhesive or a coated release substance. To accomplish his objectives, Riggsbee requires that the coupon layer be the substrate for “casting” a thin extruded film of resin so as to retain detachability without damage to the substrate and without leaving a tacky residue.
U.S. Pat. No. 5,628,858, to Petrou “LABEL SYSTEM FOR REUSABLE CONTAINERS AND THE LIKE”, requires the use of a multilayer laminate called a “placard” having a coated release substance on one side and means on the other side for adhesively securing the placard to the container. The placard is partially transparent with instructional printing applied to one surface. Pressure-sensitive labels are placed on the exposed release-coated surface of the placard. The labels contain indicia relating to the status of the container. When the status of the container changes, the label is removed and a new label is substituted on the placard. As a preferred embodiment, the placard is provided on one face with a coated silicone release substance.
U.S. Pat. No. 5,543,191, to Dronzek, Jr. et al “DURABLE SHEETS FOR PRINTING”, teaches that composite pressure sensitive label sheets will print in hot laser printers without curling if they comprise at least three layers: A. at least one base layer having a pressure sensitive adhesive on the bottom face, B. a printable surface layer on top of the base layer or layers, and C. a strippable protective backing on the pressure sensitive adhesive coated bottom face on the base layer or layers and if the thermal expansion or contraction characteristics of the printable layer B and the protective backing C are the same or substantially the same. In preferred embodiments, the backing C or layer A will be adhered to the pressure sensitive adhesive through a release coating, such as a poly(tetrafluoroethylene film) or more preferably a silicone resin, for the labels.
To summarize, in the present state of the art, it is known to use a laminated support structure (“placard”) having a release-coated surface on one side and a pressure sensitive adhesive on the other backed by a removable release liner for attachment to a pressure sensitive coating of a label (Petrou). It is also known that one way to eliminate the use of a release coating on a support structure is to bond a thermoplastic film to a label by heat and pressure and, as well, not to use an adhesive (Riggsbee). Finally, it is known, but not preferable, to substitute a poly(tetrafluoroethylene) film for a silicone coating to release a support structure when the release liner is disposed of after only one use (Dronzek, Jr. et al).
It has now been found that durability of the multi-use label support structure will be vastly increased and reliability of the labeling and, especially, the re-labeling process will be enhanced by providing and using as a support structure a resin film having a controlled release surface made without using a coated release substance. “Durability” is increased, without limitation, in terms of ultraviolet (UV)-light resistance, abrasion resistance, anti-corrosives resistance, sterile packaging conditions resistance, chemical resistance, and the like. “Reliability” is enhanced by avoiding the use of a coated release substance, such as a silicone release coating, which, once abraded through the coating, causes the pressure sensitive adhesive-backed label or labels to stick and possibly even tear by contact with the underlying surface, and/or to distort or lose valuable printed information. Re-labeling is significantly improved because the substrate lends itself to use over and over again. Additionally, many temporary labels are removed and reapplied to other containers or areas for control and tracking purposes at various steps of manufacturing, packaging, storage and distribution, so the improved removability of the labels provided by the present invention is advantageous.
Accordingly, an object of the invention is to provide a durable support structure for use in labeling and relabeling using pressure-sensitive adhesive-backed labels.
Another object is to provide a durable support structure for use in labeling and relabeling using an adhesive-backed laminate having a disposable liner covering the adhesive.
These and other objects of the invention will become apparent from the present specification.